Name
XMLType.existsNode — Tests node existence having evaluated given XPATH expression.
Synopsis
XMLType.existsNode
(
|
in xpath_expn varchar , |
in
namespace_map
varchar
); |
Description
The member function calculates the given XPATH expression
xpath_expn
using
the XML entity of the instance as a context node. If a namespace_map
parameter
is given then the function adds namespace declarations from this parameter into the beginning of
xpath_expn
before the evaluation.
The function returns 1 if the first result of XPATH evaluation is a node or 0 if there are no results or if the first result is not a node.
Parameters
xpath_expn
A text of XPATH expression to evaluate.
namespace_map
A string that is a list of namespace prefix declarations delimited by whitespace characters.
If the xpath_expn
expression also contains a list of declarations then these two
lists are concatenated.
Return Types
The function returns integer 1 or 0
Examples
Example 24.547. A table with an XMLType column
This populates a table with XML data and then reports which rows contain 'empno' element inside 'emp'.
create table TEST_XMLS (I integer primary key, XMLVAL XMLType);
insert into TEST_XMLS values (1, XMLType('<emp><empno>221</empno><ename>John</ename></emp>'));
insert into TEST_XMLS values (2, XMLType('<po><pono>331</pono><poname>PO_1</poname></po>'));
insert into TEST_XMLS values (3, XMLType('<oil-rig
xml:id="14a" water="0.413"/><oil-rig
xml:id="14b" water="0.402"/>'));
select e.I, e.XMLVAL.existsNode('/emp/empno')
from TEST_XMLS as e
I callret
INTEGER NOT NULL INTEGER
_______________________________________________________________________________
1 1
2 0
3 0
3 Rows. -- 00000 msec.